Detachable feed leg structure for rock drills



June 8, 1954 J. c. HOUSTON DETACHABLE FEED LEG STRUCTURE FOR ROCK DRILLs Filed Sept. l2, 1951 IN V EN TOR.

Patented June 8, 1954 DETACHABLE FEED LEG STRUCTURE FOR ROCK DRILLS James Curtis Houston, Noranda, Quebec, Canada Application September 12, 1951, Serial No. 246,237

2 claims. l

This invention relates to rock drills and more particularly to detachable telescopic feed leg c onstruction for converting hand-held rock drills to stoper drills.

The term stoper drill is a semi-technical term generally applied to a rock drill specially designed to drill vertical or steeply inclined holes and being so designed is not suitable for universal rock drill work. This type of drill is generally (Cl. Z55-52) mounted on one end of the casing, and a pair of tubular mounting blocks I2 also mounted on said end of the casing. The casing contains a first piston I4 and a second piston I5. Air under pressure is adapted to be supplied to the interior of casing LI3 through valve I!) which is the standard type of valve conventionally employed in the supply of air to pneumatic drills. To this end, the valve is provided with the usual air inlet con- Of Considerable Weight and COIlSeduenly Causes l0 nection IB, air passage 25 communicating with undue operator fatigue. Furthermore recent dechamber 26, and air passage 21 also communicatvelopments in rock drilling have provided caring with chamber 26 and leading to the interior bide-tipped drill rods and carbide insert rockof casing i3. Ahand holding support is mounted drill bits which are capable of drilling many feet on the valve I8 and is rotatable to regulate the of rock before reconditioning is necessary. The 15 air supplied from chamber 26 to passage 2l, all basic design of present day stopers will not allow in the usual manner. The usual air release passufficient extension of the stoper leg to take full sage 28, leading from passage 21 and controlled advantage of this new drilling equipment. by button 29, is also provided.

A number of devices are now available for con- The tubular mounting blocks i2 are rigidly Veltng Some types 0f light-Weight rock drill fOr 2o secured in parallel relation to the casing I3 and 11S@ aS SODSI drills. Each has been developed for each provides a cylindrical socket I2a for recep- 0116 Specc type 0f rock drill and iS hence not tion of a respective side rod I8. The side rods I8 adaptable to universal use. One such device is are of the same diameter and of slightly greater mounted parallel to the drill but oiiset therelength than the side rods which are standard from in such a manner that the converted drill 2:, equipment with the hand held rock drill. The iS poorly balanced and very difiicult to operate. side rods I s serve to secure the telescopic feed Other devices have a special back head for the leg c to the rock drill I, as shown. Ends I9 of the IOck drill Which fOlmS an integral part 0f the mounting blocks I2 abut against shoulders 20 on stoper leg so that the rock drill may not easily be the back head 5, such shoulders 20 being the conconverted for drilling at holes. s., Ventional side rod-receiving shoulders of a rock It is an object of the present invention to prodrill.

Vide a unitary attachment, fOI @Onvertng any Piston Id operates within the casing I3 and ordinary light-weight rock drill to a stoper drill, piston I5 within piston I4.

which is simple in construction and easily and Piston I4 has an end closure 3!) and a hollow readily attached t0 or detached from any lghi- 3;. tubular member 3| extending outwardly thereweight rock drill without requiring auxiliary parts from and providing a passage 31a leading to the or changes in the rock drill itself. interior of piston I4. In the retracted position A further object of the invention is to provide of piston I4, as shown in Figure 1, the passage a detachable feed leg structure which may be 3m in member 3| is closed by engagement of mounted directly in line with any normal rock 4 the latter with a socket member 32 carried by drill, thus reducing operator fatigue. cap I l. Piston I5 has a closed end 33. In oper- The invention will now be described with refation, air initially supplied to casing I3 through erence to the accompanying drawings in which; passage 21 enters space 3d surrounding socket Figure l iS a plan View of the converted drill member 32. Such air moves piston I4 outwardly, Showing the detachable feed les in SeClOIl, and 4,-, piston I5 moving outwardly therewith. Since the Figure 2 is an elevation view of the converted initial air supply does not enter the interior of drill. piston Id (passage 3m being closed by socket In the drawings I is a rock drill of any well member 32), piston I5 does not move outwardly known type having a Chllk 2, a from? head 3, a with relation to piston Id. When member 3I cylinder 01 body SGCOD 4, and a back head 5. 50 clears socket member 32, air under pressure ows Mounted in the back head 5 is the usual throttle through passage 3m into the interior of piston valve 6, air inlet 'i' and water inlet 8. I. Normally, the initial air supply is not sum- The telescopic feed leg in accordance with the cient to move piston I5 outwardly from piston I4 invention comprises an outer casing or cylinder until the latter is fully extended, when, if desired, I3 having a closure cap I I, a control valve I0 55 an increased supply of air is admitted to the casing through valve i@ to Cause such outward movement of piston I5. A tip 2i is mounted in the outer end of the piston l5.

A tip 2l is mounted in the outer end of the piston I5.

The use of the detachable telescopic feed leg assembly enables any light-Weight hand-held rock drill to be easily converted to a stoper drill. The standard side rods (not shown) are removed from the rock drill l. The telescopic feed leg 9 is placed in axial alignment with the drill l so that the mounting blocks l2 seat against the shoulders 20 on the standard back head 5. The extra length side rods i8 are now inserted and tightened and the in-line stoper drill is ready for operation.

The operation of the converted drill is the same as any standard stoper drill. The throttle valve 6 controls the air and water supply to operate the rock drill i. to permit air to enter the feed leg to extend the rst extension leg or piston M and then the second piston i5 as required depending on the depth of the hole to 4be drilled.

I claim:

l. In a roc-lr drill having a closed back head and shoulders thereon adjacent said back head, a feed leg structure detachably mounted on said drill and comprising a tubular casing closed at one end and having therein at least one fluid operated member arranged to project from the other end of the casing and having a supportengaging tip on its outer end, means for admitting fluid to the casing to move said member, mounting blocks secured to the casing and each having a socket therein in parallel relation to the casing, each said block also having an end portion projecting beyond said closed end, said end portions abutting said shoulders to maintain The control valve IB is actuated said closed end in spaced relation to said closed back head, and side rods extending through said sockets and securing said feed leg structure to the rock drill.

2. In a detachable feed leg for converting a lightweight hand-held rock drill to a stoper drill, a feed leg structure comprising a casing, a cap mounted in and closing one end of the casing, a fluid operated piston mounted in the casing and extending from the other end thereof, said piston having a support-engaging tip on its outer end, means for admitting fluid to the casing to move said piston, said means including a fluid-regulating control valve mounted on the casing adjacent the closed end thereof, and a pair of supporting blocks rigidly connected to and adjacent the closed end of the casing, each said block having a side rod receiving socket in parallel relation to the casing and an end portion projecting beyond said closed end, the ends of said end portions being arranged to abut said rock drill to space said closed end therefrom, and' side rods extending through said sockets and arranged to secure said feed leg structure to the rock drill.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 13,646 Goodrum Oct. 9, 1855 929,111 Richards July 27, 1909 1,162,249 OBrien Nov. 30, 1915 1,740,701 Osgood Dec. 24, 1929 1,750,415 Marsh Mar. 1l, 1930 1,860,946 Nell May 31, 1932 2,095,692 Everheart Oct. l2, 1937 2,210,532 Feucht Aug. 6, 1940 

